Improved vulcanizing flase foe dentists



@f tstrs vsiwt @fitte LEVI W. DOWLIN, OF SHERBROOKE, CANADA EAST.

I Letters Patent No. 61,174, elated Jam/,ary 15, 1867.

IMIBOVED VULCANIZING PLASK FOB. DENTISTS.

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TO ALL WHOM IT MAY CONGERN:

Be it known 4that I, L. W. DOWLIN, nown` residing in Sherbrooke, inthecounty of Sherbrooke, Cana-da East, have invented an improvedVulcanizin'g Flask for packing rubber around artificial teeth; and dohereby declare that the following is a full and exact descriptionthereof, reference being had to the accompanying draw-4 ings, makingpart of this specification- Figure l being a side view of the tlask.

Figure 2, a bottom view thereof.

Figure 3, a central verticalsection thereof ina plane, indicated by theline rex, iig. 2.

Figure 4, a bottom View of the upper part.

Figure 5,a bottom view of themiddle part.

Figure 6, a top view of the lower part of'the flask.

Like letters designate corresponding parts in all of the figures.

Instead of a single part, as C, in which the die is formed, and intowhich the teeth and rubber are placed and packed by Aforcing a coverdown upon the said die part as in ordinary asks, I employ a separatemiddle'part, B, and a counter-die part, marked A, in addition to the diepart C. The teeth or blocks D D are set in the middle i'lask part B,4and then the two parts B and C are brought together and secured by twoscrew-bolts L and nuts t' z'. The rubber is placed in over.. die part C,around the teeth D D, being carefully packed around the rivets dd. Thenthe counter-die part A is gradually forced. down upon all by means ofscrewebolts fff, screwing into screw-lugs g g, or secured by nuts, untilthe rubber is completely shaped and packed. Several important advantagesare accomplished by this construct-ion of the ask over those heretoforein use. First, there is never any fear or danger of having too much ortoo little rubber, as in the common flasks, in which there is no remedyin either case; for in this, by using a small excess of rubber, thatsurplus, is forced out by pressing down the top part A, or else the saidpart is left partly open, and still makes the ,packing complete;whereas, in the old form, the two parts must be brought together, orelse the teeth are not set in place in the die.. Second, there is nodanger of breaking or displacing the teeth by this, since they are ttedin the die part before the packing in of the rubber, Aand the pressureis applied. Third, there is no danger of breaking the ask or any partthereof` in screwing the parts together, since there is no obstaclewhich impedes the bringing together of the parts, and there is no quickWearing out of the screws, as is the case when so much force has'to beapplied in the usual manner. Fourth, there is never any necessity ofgrinding o' the teeth to make a tit if the parts are not broughtcompletely together, as is vthe case with the common flask; for in thisthe position of the teeth is exactly determined by uniting the parts Band C ,before the packing of the ruber is done. Fifth, there is a largesaving of rubber, since all the surplus is pressed out and saved, butnot so with the ordinary flasks. Sixth, every particle of wax is readilyremoved from the rivets of the teeth with this fiask; since they arereadily reached and operated upon.

What I claimas my invention, and desire to secure by Letters Patent, is

The employment of the middle part B of the iiask, substantially as andfor the purpose herein specified.

I also claim the separate union of the parts B and 'C before the rubberis packed in by means of screw-bolts h or their equivalent,substantially as and for the purpose herein set forth.

I also claim the combination and arrangement of the counter-die part Awith the parts B and C, substantially as herein speciiied. g K Y Theabove specification of my improved vuleanizing ask signed by me thiseighth day of Novenmber, 1865.

LEVI W. DOWLIN.

Witnesses:

A. J. WooDwARD, J. G. ROBERTSON.

